High-Performance Capacitance-to-Digital Converters for Sub-nm Displacement Sensing: A Review
Hui Jiang, St. Nihtianov · Engineering Sciences · 2020
This paper presents a review of energy-efficient capacitance-to-digital converters specifically intended for precision displacement measurement.Apart from achieving good energy efficiency, such capacitance-to-digital converters must achieve high accuracy and stability, as well as high immunity to power-supply and common-mode variations.Various capacitance-to-digital converter architectures are discussed, beginning with traditional designs in which a capacitance-to-voltage converter is used to drive an analog-to-digital converter, and moving on to more recent works which attempt to increase energy efficiency and reduce complexity by eliminating the capacitance-to-voltage converter.The performance of these topologies, and in particular their energy efficiency, will be compared and summarized.Moreover, a novel capacitance-to-digital converter topology for sub-nm displacement sensing with an electrically floating target is described.